Polypodium adianthoides Burm. f.

Mazumdar, Jaideep, Callmander, Martin W. & Fumeaux, Nicolas, 2019, Typification and nomenclature of the ferns described in N. L. Burman’s Flora Indica, Candollea 74 (1), pp. 93-109 : 98-100

Polypodium adianthoides Burm. f. , Fl. Ind.: 234. 1768.

Lectotypus (designated here): INDONESIA: sine loco, s.d., Pryon s.n. ( G-PREL [ G00800154 ]!) ( Fig. 4 ) .

Notes. – In the protologue, BURMAN (1768) cited an illustration ( PETIVER, 1712: 67 (sphalm. “69”), tab. 2, fig. 9) and a Pryon collection. The single specimen representing original material is a Pryon specimen with no clear origin. MERRILL (1921: 337) mentioned a probable origin from Java. Pryon left on the 7 th December 1756 as head surgeon for the Dutch East India Company (VOC: Vereenigde Oostindische Compagnie) on board the Vrouwe Petronella Maria vessel to Batavia [Jakarta] ( FLORIJN, 1987). The vessel arrived in Batavia on the 21 st July 1757 ( BRUIJN et al., 1979). Before his definitive settlement in Java in 1760, Pryon served on two vessels in the region between 1757 and 1760 ( FLORIJN, 1987). It is clear that Pryon also collected outside Java. He must have collected in other VOC settlements, elsewhere in Indonesia and possibly in India. Correspondence between Pryon and N.L. Burman kept in the archives of the University of Amsterdam (see STEENIS-KRUSEMAN, 1958) dated 1764 give no further information on Pryon’s itinerary (A. Stork, pers. comm.).

The Pryon specimen in G-PREL ( Fig. 4 ) clearly represents a species of the genus Rumohra Raddi. It corresponds to Rumohra adiantiformis (G. Forst.) Ching , showing similar frond morphology, leathery lamina, and free veins. BURMAN (1768) ’s Polypodium adianthoides predates FORSTER (1786) ’s P. adiantiforme G. Forst. In order to allow the further use of a well-known and widely used fern name (A. Smith, pers. comm.) and to avoid disadvantageous nomenclatural changes entailed by the strict application of the ICN rules ( TURLAND et al., 2018: Art. 14.1), a proposal to conserve Forster’s name over Burman’s is in preparation.

Rumohra adiantiformis is widely distributed in the neotropics ( South and Central America and the West Indies ), the paleotropics ( Southern Africa , Madagascar, the Mascarenes , New Guinea), Australia and New Zealand. It is also widely cultivated and known as the “leatherleaf fern”. The type locality is unknown but it has been most probably collected from a cultivated specimen somewhere in Asia or Southeast Asia, and not in its natural range in the Cape region.

A recent molecular phylogeny showed that the species represents a polyphyletic taxon and includes six lineages in distinct geographical regions ( BAURET et al., 2017). Rumohra adiantiformis may therefore represent several cryptic species.

Figures

Fig. 4. – Lectotype of Polypodium adianthoides Burm. f. in G-PREL.